Personal care compositions comprising various combinations of detersive surfactants and conditioning agents are known. These products typically comprise an anionic detersive surfactant in combination with a conditioning agent such as silicone, hydrocarbon oil, fatty esters, or combinations thereof. These products have become more popular among consumers as a means of conveniently obtaining hair or skin conditioning and cleansing performance all from a single personal care product.
Many personal care compositions, though, do not provide sufficient deposition of conditioning agents onto hair and skin during the cleansing process. Without such deposition, large proportions of conditioning agent are rinsed away during the cleansing process, and, therefore, provide little or no conditioning benefit. Without sufficient deposition of the conditioning agent on the hair and skin, relatively high levels of conditioning agents may be needed in the personal care composition to provide adequate conditioning performance. However, high levels of a conditioning agent can increase raw material costs, reduce lathering, and present product stability concerns.
Obtaining good deposition of a conditioning agent is further complicated by the action of detersive surfactants in the personal care composition. Detersive surfactants are designed to carry away or remove oil, grease, dirt, and particulate matter from the hair and skin. As a result, the detersive surfactants can interfere with deposition of the conditioning agent and can remove both deposited and non-deposited conditioning agent during rinsing. Consequently, after rinsing, the deposition of the conditioning agent onto the hair and skin is reduced, which, in turn, reduces conditioning performance. Therefore, to achieve desired conditioning performance with a given conditioning agent, a specific anionic surfactant system may be needed for use in combination with the given conditioning agent.
One method for improving deposition of a conditioning agent involves the use of certain cationic deposition polymers. Commonly used cationic deposition polymers include natural polymers, such as guar gum polymers that have been modified with cationic substituents. Guar gum polymers are galactomannans containing two mannose monomers with a glycoside linkage and one galactose monomer attached to a hydroxyl group of the mannose monomers (i.e., guar gum polymers have a mannose to galactose ratio of 2:1 on a monomer to monomer basis). Selecting a cationic guar deposition polymer with sufficient charge density and molecular weight, in combination with an optimized surfactant system, results in sufficient deposition of conditioning agents. However, to achieve this sufficient deposition of conditioning agents in shampoo or body wash compositions using a cationic guar polymer, a relatively high level of such cationic guar polymer generally must be deposited on the hair or skin. Moreover, the cost of such cationic guar polymer is relatively high. As a result, incorporation of cationic guar polymer can add to the manufacturing costs of such personal cleansing compositions.
Accordingly, there is a continuing need for a personal cleansing composition which delivers superior conditioning benefits to hair and/or skin, without a reduced cleansing performance, through relatively low deposition of an inexpensive cationic or amphoteric polymer in combination with a particular anionic surfactant system.